Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Azorius Signet

Dawn's Truce

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
You and permanents you control gain hexproof until end of turn. If the gift was promised, permanents you control also gain indestructible until end of turn.

Immortal Servitude

Return each creature card with mana value X from your graveyard to the battlefield.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Mass Appeal

Etchings of the Chosen

As this enchantment enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{1}, Sacrifice a creature of the chosen type: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Have

Island

Herald of Hoofbeats

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Other Knights you control have horsemanship.

Spear of Heliod

Creatures you control get +1/+1.
{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Azorius Chancery

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Deserted Beach

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Sidar Jabari of Zhalfir

Eminence — Whenever you attack with one or more Knights, if Sidar Jabari is in the command zone or on the battlefield, draw a card, then discard a card.
Flying, first strike
Whenever Sidar Jabari deals combat damage to a player, return target Knight creature card from your graveyard to the battlefield.

Orzhov Basilica

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Ghostly Prison

Knight of the White Orchid

First strike
When this creature enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

The Circle of Loyalty

Affinity for Knights (This spell costs {1} less to cast for each Knight you control.)
Creatures you control get +1/+1.
Whenever you cast a legendary spell, create a 2/2 white Knight creature token with vigilance.
{3}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.

Shineshadow Snarl

As this land enters, you may reveal a Plains or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {B}.

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Templar Knight

Vigilance
{W}, Tap five untapped attacking creatures you control named Templar Knight: Search your library for a legendary artifact card, put it onto the battlefield, then shuffle.
A deck can have any number of cards named Templar Knight.

Cathars' Crusade

Whenever a creature you control enters, put a +1/+1 counter on each creature you control.

The Immortal Sun

Players can't activate planeswalkers' loyalty abilities.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}

Desolate Mire

Orzhov Signet

Whip of Erebos

Creatures you control have lifelink.
{2}{B}{B}, {T}: Return target creature card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step. If it would leave the battlefield, exile it instead of putting it anywhere else. Activate only as a sorcery.

Command Tower

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Vanquisher's Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
Whenever you cast a creature spell of the chosen type, draw a card.

Sol Ring

Haytham Kenway

Protection from Assassins
Other Knights you control get +2/+2 and have protection from Assassins.
When Haytham Kenway enters, for each opponent, exile up to one target creature that player controls until Haytham Kenway leaves the battlefield.

Seachrome Coast

This land enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Echoing Return

Return target creature card and all other cards with the same name as that card from your graveyard to your hand.

Fetid Heath

{T}: Add {C}.
{W/B}, {T}: Add {W}{W}, {W}{B}, or {B}{B}.

Morphic Pool

This land enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Prairie Stream

({T}: Add {W} or {U}.)
This land enters tapped unless you control two or more basic lands.

Benalish Marshal

Patchwork Banner

As this artifact enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Greymond, Avacyn's Stalwart

As Greymond, Avacyn's Stalwart enters, choose two abilities from among first strike, vigilance, and lifelink.
Humans you control have each of the chosen abilities.
As long as you control four or more Humans, Humans you control get +2/+2.

Sigiled Sword of Valeron

Equipped creature gets +2/+0, has vigilance, and is a Knight in addition to its other types.
Whenever equipped creature attacks, create a 2/2 white Knight creature token with vigilance that's attacking.
Equip {3}

Port Town

As this land enters, you may reveal a Plains or Island card from your hand. If you don't, this land enters tapped.
{T}: Add {W} or {U}.

Plains

Herald's Horn

As this artifact enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Valiant Knight

Other Knights you control get +1/+1.
{3}{W}{W}: Knights you control gain double strike until end of turn.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Knight Exemplar

First strike (This creature deals combat damage before creatures without first strike.)
Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)

And They Shall Know No Fear

Choose a creature type. Creatures you control of the chosen type get +1/+0 and gain indestructible until end of turn.

Knights' Charge

Whenever a Knight you control attacks, each opponent loses 1 life and you gain 1 life.
{6}{W}{B}, Sacrifice this enchantment: Return all Knight creature cards from your graveyard to the battlefield.

Marshal of Zhalfir

Other Knights you control get +1/+1.
{W}{U}, {T}: Tap another target creature.

Dimir Signet

Counterspell

Isolated Chapel

This land enters tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Negate

Vodalian Wave-Knight

Whenever you draw a card, put a +1/+1 counter on each other Merfolk and/or Knight you control.

Haakon, Stromgald Scourge

You may cast this card from your graveyard, but not from anywhere else.
As long as Haakon is on the battlefield, you may cast Knight spells from your graveyard.
When Haakon dies, you lose 2 life.

Flare of Fortitude

You may sacrifice a nontoken white creature rather than pay this spell's mana cost.
Until end of turn, your life total can't change, and permanents you control gain hexproof and indestructible.

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Shattered Sanctum

This land enters tapped unless you control two or more other lands.
{T}: Add {W} or {B}.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Knight of Dusk's Shadow

Menace (This creature can't be blocked except by two or more creatures.)
Your opponents can't gain life.
{1}{B}: This creature gets +1/+1 until end of turn.

Swamp

Guardian of Faith

Flash
Vigilance
When this creature enters, any number of other target creatures you control phase out. (Treat them and anything attached to them as though they don't exist until their controller's next turn.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.